The objective of this project is to determine the precise effect of Centrophenoxine on neuronal lipofuscin pigment. In the current year the method of isolation of lipofuscin developed by Siakotos has been modified for small samples of brain tissue. The cerebrum, cerebellum and brainstem were dissected out from mice of different ages (2, 6-8, 12-14, 18-20, 24-26 months) and lipofuscin pigment was isolated by sucrose density gradient and differential centrifugation method. The purity of the isolated samples were tested by histochemical, fluorescence and EM techniques. Final measurement of the pigment was carrried out quantitating the activity of acid phosphatase by spectrophotometry. Young and old mice are being treated with Centrophenoxine (80 mg/kg of body weight) for variable periods. The lipofuscin pigment will be quantitated from the brain samples of control and treated young and old mice by similar methods. The study is expected to indicate whether the drug can reduce lipofuscin pigment already formed in old animals and whether it can reduce or stop it completely in young animals.